Luminal prosthesis and implant device

ABSTRACT

An inexpensive small-sized screen printing machine having low redundancy and high production efficiency and applicable to a dual conveying-type component mounting machine. A pair of substrate supporting tables juxtaposed in a specific direction is provided. Screen printing is alternately performed by a single print executing section in a common area which can be shared by the two substrate supporting tables. In doing so, when one substrate supporting table located at a print position among the pair of substrate supporting tables starts exiting the print position, the other substrate supporting table starts entry to the print position.

INTRODUCTION

The invention relates to a device. In one aspect the invention relatesto a gastrointestinal implant device.

There are several procedures and devices for treatment of obesity.Whilst many of these devices are successful in the short term variousproblems can arise because the patient does not achieve a feeling ofsatiety (fullness) after eating.

STATEMENTS OF INVENTION

According to the invention there is provided a luminal prosthesiscomprising:

-   -   a first part which is adapted to be retained in a lumen; and    -   a second part which is connected to the first part such that a        force applied to the second part is at least partially isolated        from the first part.

The second part may be adapted for mounting of a device such as a valve.

The prosthesis may comprise a connector between the first part and thesecond part. The connector may comprise at least one tether. Theconnector may comprise at least one strut. The connector may comprise atleast one wire.

In one case the first part and the second part are formed from a singleprecursor.

The precursor may comprise one continuous stent which is folded to formthe first part and the second part.

In one case the second part is radially inward of the first part.

The first part may comprise a bulbous region.

The second part may comprise a scaffold-receiving region.

The prosthesis may comprise a proximal flare. There may be a transitionregion between the bulbous region and the proximal flare.

In one case the prosthesis comprises a bulbous region, a proximal flareand a scaffold receiving region.

The proximal flare may be of open mesh construction. The proximal flaremay be adapted to resist axial movement of the prosthesis. The proximalflare may be at least partially coated. In one case the proximal flarehas a peripheral region which is coated.

In one embodiment the bulbous region is partially coated.

In one case the scaffold receiving region is stiff relative to thebulbous region.

The prosthesis may comprise a transition region between the proximalflare and the bulbous region. The transition region may be of open meshsoft construction.

The prosthesis may be of braided mesh construction.

In one aspect the invention provides a luminal prosthesis comprising anouter region and an inner region connected to the outer region, theinner region being adapted for mounting of a device such as a valve. Theinner region may be connected to the outer region by a connecting meanssuch as struts and/or wires. The inner region may be formed by anextension of the outer region. The inner region and the outer region areformed by one continuous stent folded to form inner and outer regions.In one case the luminal prosthesis comprises a proximal flare, a bulbousregion, and a scaffold receiving region.

In one embodiment the prosthesis has a reinforcement to facilitateradial compression during loading and to limit radial expansion. Thereinforcement may extend around at least part of the circumference ofthe stent. The reinforcement may comprise at least one loop.

In one case the reinforcement is non-distensible. The reinforcement maybe of flexible material. In one case the reinforcement is of a polymericor metallic thread. The reinforcement may be a material selected fromone or more of the group comprising monofilament or braidedpolypropylene suture or a stainless steel wire.

The invention also provides luminal self expanding prosthesis having areinforcement to facilitate radial compression during loading and tolimit radial expression. In one case the reinforcement extends around atleast part of the circumference of the stent. The reinforcement maycomprise at least one loop. The reinforcement may be non-distensible.The reinforcement may be of a flexible material. The reinforcement maybe of a polymeric or metallic thread. The reinforcement may be of amaterial selected from one or more of the group comprising monofilamentor braided polypropylene suture or a stainless steel wire.

The invention also provides a gastrointestinal implant device comprisinga prosthesis of the invention.

Also provided is a gastrointestinal implant device comprising:

-   -   a sleeve for extending into the duodenum;    -   an artificial valve for placement at the pylorus to control flow        from the stomach into the duodenal sleeve; and    -   a support structure for the valve, the support structure        comprising a scaffold to which the valve is mounted and a        luminal prosthesis of the invention.

According to the invention there is provided a luminal prosthesiscomprising an outer region and an inner region connected to the outerregion, the inner region being adapted for mounting of a device such asa valve.

In one embodiment the inner region is connected to the outer region by aconnecting means such as struts and/or wires.

In another embodiment the inner region is formed by an extension of theouter region. The inner region and the outer region may be formed by onecontinuous stent folded to form inner and outer regions.

In one case the luminal prosthesis comprises a proximal flare, a bulbousregion, and a scaffold receiving region

The invention also provides a gastrointestinal implant device comprisinga prosthesis of the invention.

The invention provides a gastrointestinal implant device comprising:

-   -   a sleeve for extending into the duodenum;    -   an artificial valve for placement at the pylorus to control flow        from the stomach into the duodenal sleeve; and    -   a support structure for the valve, the support structure        comprising a scaffold to which the valve is mounted and a        luminal prosthesis of the invention.

According to the invention there is provided a gastrointestinal implantdevice comprising:

-   -   a sleeve for extending into the duodenum; and    -   an artificial valve for placement at the pylorus to control flow        from the stomach into the duodenal sleeve; and    -   a support structure for the valve.

The invention also provides a gastrointestinal implant devicecomprising:

-   -   a sleeve for extending into the duodenum;    -   an artificial valve for placement at the pylorus to control flow        from the stomach into the duodenal sleeve; and    -   a support structure for the valve, the support structure        comprising a scaffold to which the valve is mounted and a        luminal prosthesis, the luminal prosthesis comprising a proximal        flare, a bulbous region, and a scaffold receiving region.

In one embodiment the scaffold receiving region is located intermediatethe proximal end and the distal end of the luminal prosthesis.

The scaffold receiving region may be located between the proximal flareand the bulbous region.

In one embodiment the valve is configured to open only when a pre-setback pressure on the valve has been overcome.

In one embodiment the support structure comprises a scaffold to whichthe valve is mounted. The support structure may comprise a luminalprosthesis.

In one case the support structure comprises a scaffold to which thevalve is mounted and a luminal prosthesis. The scaffold may bereleasably mountable to the luminal prosthesis.

In one embodiment the sleeve is mounted to the support structure. In onecase The sleeve is releasably mountable to the support structure. In onecase the support structure comprises a scaffold and the sleeve ismounted to the scaffold.

In one embodiment the support structure comprises a stent-likestructure.

In one case the support structure comprises a stent-like scaffold.

In one embodiment the support structure comprises a luminal prosthesisfor deployment at the pylorus and a scaffold to which the valve ismounted, the scaffold being releasably mountable to the pre-deployedluminal prosthesis. The scaffold may be releasably engagable with theluminal prosthesis. The scaffold may comprise engagement elements whichare releasably engagable with the luminal prosthesis. In one case theengagement elements comprise protrusions which are releasably engagablewith the luminal prosthesis.

In one embodiment the luminal prosthesis comprises a mesh. The mesh maybe coated with a coating. The protrusions may engage with the mesh. Theprotrusions may penetrate the mesh.

In one embodiment the device comprises a release means for releasing thescaffold from engagement with a pre-deployed luminal prosthesis. Therelease means may comprise means for reducing the diameter of at least aportion of the scaffold. The release means may comprise a drawstringextending around the scaffold.

There may be a first drawstring extends around a proximal end of thesupport structure. There may be a second drawstring extends around adistal end of the support structure.

In one embodiment the valve is mounted to the support structure. Thevalve may be sutured to the support structure. The valve may be bondedto the support structure. The valve may be adhesively bonded to thesupport structure.

In one case a proximal end of the sleeve is mounted to the supportstructure. The sleeve may be sutured to the support structure. Thesleeve may be bonded to the support structure. The sleeve may beadhesively bonded to the support structure.

In one embodiment the support structure comprises a scaffold which is ofsubstantially uniform diameter.

In one case the support structure comprises a luminal prosthesis.

The luminal prosthesis may comprise a proximal flare. The luminalprosthesis may comprise a distal bulbous region. The luminal prosthesismay comprise a scaffold receiving region. The scaffold receiving regionmay be intermediate the proximal and distal ends of the luminalprosthesis.

In one embodiment the sleeve is of substantially uniform diameter alongthe length thereof.

In another embodiment the sleeve has a first diameter at a proximal endand a second diameter at the distal end which is larger than the firstdiameter. The sleeve may be tapered.

In one embodiment the sleeve comprises a retaining means to assist inretaining the sleeve at a desired location. The retaining means maycomprise a retaining ring. A retaining ring may be located at oradjacent to a distal end of the sleeve.

There may be a plurality of retaining rings which are axiallyspaced-apart along the sleeve.

In one case the retaining ring comprises a biasing means. The biasingmeans may comprise a flexible material which is biased into an expandedconfiguration.

In one embodiment the retaining ring is oversized with respect to thesleeve.

The device may comprise release means for releasing the retaining ringfrom engagement. The release means may comprise a drawstring.

In one embodiment the sleeve has a retracted delivery configuration andan expanded deployed configuration. The sleeve may be folded in theretracted delivery configuration.

In one embodiment the valve has a normally closed configuration and anopen configuration in which the valve is opened for stomach emptying.

In one case the valve is adapted to open automatically for stomachemptying and to return automatically to the closed configuration.

The valve may be of a viscoelastic polymeric foam which may bebiomimetic.

In one embodiment the valve comprises an outer support region, at leastthree valve leaflets, and a main body region extending between thesupport region and the valve leaflets. The valve may have a region ofco-aption of the valve leaflets in the closed configuration. The regionof co-aption may extend for an axial length of at least 1 mm.

In one embodiment the device is adapted for placement in the pyloricsphincter or valve.

In another embodiment the device is adapted for placement distal of thepyloric sphincter.

In one embodiment the support is adapted for mounting to a pre-deployedsleeve which extends into the duodenum.

The invention also provides a delivery system for a gastrointestinalimplant device, the implant device comprising an artificial valve, aduodenal sleeve and a support structure for the valve and the sleeve,the device having a retracted delivery configuration and an expandeddeployed configuration, the delivery system comprising a deliverycatheter having a distal pod for the implant device in the retractedconfiguration; and a sleeve deployment system.

In one case the sleeve deployment system comprises:

-   -   a distal cap;    -   a fluid delivery lumen for extending through the sleeve;    -   a distal seal between the distal cap and the lumen; and    -   a proximal seal,        whereby delivery of fluid through the lumen and into the sleeve        causes the sleeve to expand from an axially retracted delivery        configuration to an axially expanded deployed configuration.

The proximal seal may be sealingly engagable with the pod for deploymentof the sleeve.

The proximal seal may be sealingly engagable with the valve fordeployment of the sleeve.

In one case the pod is detachable from the delivery catheter.

The proximal seal may comprise an inflatable balloon.

The distal seal may comprise an inflatable balloon. The delivery systemmay include a flexible tube for inflating the distal balloon.

The delivery system in one embodiment comprises a deployer for deployingthe support structure and the valve to which the support structure ismounted. In one case the deployer comprises an abutment. The abutmentmay be provided by a balloon. The deployer balloon may comprise theproximal balloon.

In one embodiment the distal cap or olive is releasably mounted to thefluid delivery lumen.

The invention also provides a gastrointestinal implant comprising asleeve for extending into the duodenum, the sleeve having a pocketcontaining a radiopaque marker. The pocket may extend at least partiallyalong the length of the sleeve.

In one embodiment the sleeve has a plurality of pockets for reception ofa radiopaque marker.

The radiopaque marker may comprise a fluid or gel. The fluid maycomprise a silicon resin filled with a radiopaque material such asbarium sulphate.

The invention also provides a method for treating obesity and/ordiabetes comprising the steps of:

-   -   providing a luminal prosthesis;    -   providing a valve mounted to a support scaffold, the valve        having a retracted delivery configuration and an expanded        deployed configuration;    -   providing a liner sleeve for lining the duodenum;    -   delivering the luminal prosthesis to a location at or distal of        the pylorus;    -   deploying the luminal prosthesis at the location in the pylorus;    -   delivering the valve and support scaffold to the location; and    -   deploying the sleeve so that the sleeve extends from the valve        and into the duodenum.

In one embodiment the method comprises deploying the valve and supportstructure so that the support structure engages with the predeployedluminal prosthesis.

In one embodiment the luminal prosthesis is deployed in the pyloricsphincter.

In another embodiment the luminal prosthesis is deployed distal of thepyloric sphincter.

The method may comprise releasing the valve support structure fromengagement with the luminal prosthesis; and withdrawing the valvesupport structure, the valve, and the sleeve from the location. Themethod may comprise repeating the appropriate steps to deploy a valve, asupport structure for the valve, and a sleeve at the desired location.

The invention further provides a method for treating obesity and/ordiabetes comprising the steps of:

-   -   providing a valve mounted to a support structure;    -   delivering the valve mounted to the support structure to a        pre-deployed sleeve which extends into the duodenum; and    -   deploying the valve so that the valve is mounted to the sleeve.

The step of deploying the valve may comprise engaging the valve supportwith the pre-deployed luminal prosthesis.

In one case the valve support is an expandable support and the methodcomprises loading the support onto a delivery catheter in a retractedform and the valve support is expandable on deployment. The support maybe self expandable. The support may be expanded by an expanding meanssuch as a balloon.

In one case the method comprises the step of releasing the valve supportfrom engagement with the luminal prosthesis. The method may compriserepositioning the valve support within the sleeve. The valve may beremoved from the sleeve.

The invention also provides a gastrointestinal implant device comprisinga pyloric valve for placement at the pylorus to control flow from thestomach into the duodenum,

-   -   the valve being of a viscoelastic foam and comprising at least        three valve leaflets,    -   the valve having a normally closed configuration and an open        configuration,    -   the valve leaflets being movable from the closed configuration        to the open configuration for flow from the stomach.

In one embodiment the valve is adapted to open automatically for stomachemptying and to return automatically to the closed configuration. Thevalve may comprise an outer support region and a main body regionextending between the support region and the valve leaflets. The valvemay have a region of co-aption of the valve leaflets in the closedconfiguration.

In one case the device comprises an anchor for anchoring the valve atthe pylorus.

In one case the anchor comprises a support structure for the valve. Theanchor may comprise a support scaffold for the valve and a luminalprosthesis to which the scaffold is mountable.

In one case the device comprises a sleeve for extending into theduodenum. The sleeve may be mounted to the valve or to an anchor for thevalve. The device may be adapted for placement in the pyloric sphincteror may be adapted for placement distal of the pyloric sphincter.

According to the invention there is provided a gastrointestinal implantdevice comprising a valve for placement at the pylorus to control therate of stomach emptying.

In one embodiment the valve has a normally closed configuration and anopen configuration in which the valve is opened for stomach emptying.

There may be a support for the valve. The support may be adapted formounting to a pre-deployed sleeve which extends into the duodenum.

In one embodiment the implant device is adapted for placement in thepyloric valve.

In a further embodiment the implant device is adapted for placementdistal of the pyloric valve.

The valve support may comprise a support structure. The supportstructure may taper outwardly. The support structure may taper inwardly.

In another case the support structure is of generally uniform diameteralong the length hereof.

The support structure may comprise a scaffold.

The support structure may comprise a stent-like structure.

In one case the device comprises mounting means for mounting the valvesupport to a pre-deployed luminal prosthesis.

The mounting means may be releasably engagable with a pre-deployed hostsupport.

The device may comprise release means for releasing the valve fromengagement with a pre-deployed host support. The release means maycomprise means for reducing the diameter of at least portion of thevalve support structure. The release means may comprise a drawstringextending around the valve support structure. There may be a firstdrawstring which extends around a proximal end of the support structure.There may be a second drawstring which extends around a distal end ofthe support structure.

In one case the valve is mounted to the support structure. The valve maybe sutured to the support structure.

The valve may be bonded to the support structure. The valve may beadhesively bonded to the support structure.

In one embodiment the valve is adapted to open automatically in the onedirection.

The invention also provides a method for treating obesity and/ordiabetes comprising the steps of:

-   -   providing a valve mounted to a support structure;    -   delivering the valve mounted to the support structure to a        pre-deployed sleeve which extends into the duodenum; and    -   deploying the valve so that the valve is mounted to the sleeve.

The step of deploying the valve may comprise engaging the valve supportwith the pre-deployed luminal prosthesis.

In one case the valve support an expandable support and the methodcomprises loading the support onto a delivery catheter in a retractedform and the valve support is expandable on deployment.

The support may be self expandable. Alternatively the support isexpanded by an expanding means. The expanding means may comprise aballoon.

In one embodiment the method comprises the step of releasing the valvesupport from engagement with the luminal prosthesis. The method maycomprise repositioning the valve support within the sleeve.

In one case the method comprises removing the valve from the sleeve.

In one embodiment the valve comprises a polymeric valve body having anouter support rim, at least three valve leaflets, and a main body regionextending between the support rim and the valve leaflets.

The invention also provides a valve comprising at least four valveleaflets, the valve having a normally closed configuration in which theleaflets are engaged and an open configuration in which the leaflets areopen. There may be at least five valve leaflets. There may be six valveleaflets.

The valve may comprise a valve body of polymeric material. The valve maycomprise an outer support region. The valve may also have a main bodyregion extending between the support region and the valve leaflets.

In one case the main body region is generally concave between the outersupport rim and a region of co-aption of the valve leaflets.

In one case the valve leaflets have a region of co-aption and the valvebody is reinforced at the region of co-aption. The valve body may bethickened at the region of co-aption.

The region of co-aption may extend for an axial length of at least 1 mm.The region of co-aption may extend for a depth of from 1 mm to 5 mm.

In one embodiment the support rim of the valve body is reinforced. Thesupport rim of the valve may be thickened.

In one embodiment the valve comprises three valve leaflets.

In another embodiment the valve comprises six valve leaflets.

The valve may be mounted to the support structure.

In one case the valve rim is sutured to the support structure.Alternatively or additionally the valve rim is bonded to the supportstructure.

In one embodiment the support structure comprises a luminal prosthesis.

In one case the luminal prosthesis extends proximally of the valve.

In another case the luminal prosthesis extends distally of the valve.

In one embodiment the luminal prosthesis extends proximally and distallyof the valve.

The luminal prosthesis may have a coating and/or a sleeve thereon. Thecoating or sleeve may be on the outside of the luminal prosthesis.Alternatively the coating or sleeve is on the inside of the luminalprosthesis.

In one embodiment the polymeric material is stable to gastric fluid forat least 3 months, for at least 4 months, for at least 5 months, for atleast 6 months, for at least 7 months, for at least 8 months, for atleast 9 months, for at least 10 months, for at least 11 months, or forat least one year.

In one case the polymeric material takes up less than about 5%, lessthan about 10%, less than about 15%, less than about 20%, less thanabout 25%, or less than about 30% by weight of water at equilibrium.

In one case the polymeric material of the valve body has a % elongationof from 50% to 3000% or 200% to 1200%.

In one case the polymeric material of the valve body has a tensilestrength of from 0.01 to 5 MPa or about 0.1 to 1.0 MPa, or about 0.25 to0.5 MPa.

In one embodiment the polymeric material has a Young's Modulus of about0.01 to 0.6 MPa, or about 0.1 to about 0.5 MPa.

In one embodiment the polymeric material of the valve body has a densityof from 0.1 g/cm³ to 1.5 g/cm³, or 0.3 to 1.2 g/cm³, or 0.8 to 0.9g/cm³, or 0.5 to 0.6 g/cm³.

In one embodiment the distance between the proximal end of the supportregion of the valve body and the distal end of the valve leaflets isless than 50 mm, or less than 40 mm, or less than 30 mm, or less than 25mm, or less than 20 mm, or less than 15 mm.

In one case the polymeric material of the valve body is of an elasticmaterial.

In another case the polymeric material of the valve body is of aviscoelastic material.

In one embodiment the polymeric material of the valve body comprises afoam. The polymeric material of the valve body may comprise an open cellfoam.

In one embodiment the polymeric material of the valve body comprises apolyurethane foam.

In one embodiment the valve is adapted to be mounted to a pre-deployedsupport structure, for example an esophageal luminal prosthesis such asa stent.

The invention also provides a valve having:

-   -   a normally closed configuration in which the valve is closed;    -   an open configuration in which the valve is opened for flow        through the valve; and    -   a support for the valve, the support being adapted for mounting        to a pre-deployed luminal prosthesis intermediate a proximal end        and a distal end of the predeployed luminal prosthesis.

In one case the luminal prosthesis has a coating and/or sleeve thereon.The coating or sleeve may be on the outside of the luminal prosthesis.Alternatively or additionally the coating or sleeve is on the inside ofthe luminal prosthesis.

The mounting means may be provided by the support structure. In one casethe mounting means comprises protrusions extending from the supportstructure. The protrusions may be adapted to engage with a pre-deployedhost esophageal luminal prosthesis.

In one embodiment the protrusion comprises a loop.

In one case the apicial tip of the protrusion is rounded.

There may be release means for releasing the valve from engagement witha pre-deployed host luminal prosthesis. The release means may comprisemeans for reducing the diameter of at least portion of the valve supportstructure.

In one case the release means comprises a drawstring extending aroundthe valve support structure. A first drawstring may extend around aproximal end of the support structure. A second drawstring may extendaround a distal end of the support structure.

In one embodiment the valve is mounted to the support structure. Thevalve may be sutured to the support structure. The valve may be bondedto the support structure. The valve may be adhesively bonded to thesupport structure.

In another case the mounting means comprises a surgical adhesive.

The invention also provides a method for providing a valve in a bodypassageway comprising the steps of:

-   -   providing a valve mounted to a support structure;    -   delivering the valve mounted to the support structure to a        pre-deployed luminal prosthesis in the body passageway; and    -   deploying the valve so that the valve is mounted to the luminal        prosthesis.

In one embodiment the step of deploying the valve comprises engaging thevalve support with the pre-deployed luminal prosthesis.

The valve support may be mechanically engaged with the pre-deployedluminal prosthesis.

In one case the valve support comprises a protrusion and the methodcomprises aligning the protrusion with an aperture in the endoluminalprosthesis and engaging the protrusion in the aperture.

In one embodiment the valve support is an expandable support and themethod comprises loading the support onto a delivery catheter in aretracted form and the valve support is extendable on deployment.

The support may be self expandable or the support is expanded by anexpanding means such as a balloon.

In one embodiment the method comprises the step of releasing the valvesupport from engagement with the luminal prosthesis.

The method may involve repositioning the valve support within theprosthesis. The method may comprise removing the valve from theprosthesis.

In one embodiment the luminal prosthesis extends proximally of thevalve. The prosthesis may comprise a self expanding plastics mesh. Theprosthesis may apply a radial force of less than 1.9 kPa.

In one embodiment there are anchors for mounting the prosthesis in situ.The anchors may be adapted to extend through the mesh of the prosthesis.

In one embodiment the length of the valve from the proximal end of thesupport region to the distal end of the valve leaflets is less than 50mm, less than 40 mm, less than 30 mm. The length of the valve may beapproximately the same as the outer diameter of the support region ofthe valve. The length of the valve may be approximately 23 mm.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clearly understood from the followingdescription thereof given by way of example only, in which:

FIG. 1 is an isometric view (from above) of a valve according to theinvention;

FIG. 2 is an isometric view (from below) of the valve;

FIG. 3 is a top plan view of the valve;

FIG. 4 is an underneath plan view of the valve;

FIGS. 5 and 6 are elevational views of the valve;

FIGS. 7 and 8 are isometric, partially cut-away sectional, views of thevalve;

FIGS. 9 and 10 are cross sectional views of the valve;

FIG. 11 is a cross sectional view of the valve in a normally closedconfiguration;

FIG. 12 is a cross sectional view of the valve in an open configurationin response to a force;

FIG. 13 is a cross sectional view of the valve returned to the closedconfiguration after opening to flow;

FIG. 14 is an isometric view (from above) of the valve in a normallyclosed configuration;

FIG. 15 is an isometric view of the valve in a partially openconfiguration in response to a force;

FIG. 16 is an isometric view of the valve in a fully open configurationin response to a force;

FIG. 17 is an isometric view of a prosthesis;

FIG. 18 is an elevational view of the valve of FIGS. 1 to 16 beingmounted to and in position on the prosthesis of FIG. 17;

FIG. 19 is another view of the valve mounted in a prosthesis;

FIGS. 20 and 21 are isometric views of a sleeved or coated prosthesis;

FIG. 22 is an isometric view of the prosthesis of FIGS. 20 and 21 with avalve of FIGS. 1 to 16 in position;

FIG. 23 is an elevational view of part of the prosthesis of FIG. 22 inposition;

FIG. 24 is an isometric view of a valve according to another embodimentof the invention;

FIG. 25 is an elevational view of the valve of FIG. 24;

FIG. 26 is an isometric view of another valve according to the inventionwith a distally outward tapering support structure;

FIG. 27 is an elevational view of the valve of FIG. 26.

FIG. 28 is an isometric view of another valve according to the inventionwith a distally inward tapering support structure;

FIG. 29 is an elevational view of a luminal prosthesis with a valve andassociated support structure in place;

FIG. 30 is an enlarged view of the luminal prosthesis and valve supportstructure of FIG. 29;

FIGS. 31 and 32 are enlarged views of one mounting detail of a valvesupport structure to a luminal prosthesis;

FIGS. 33 to 37 are views of a valve being deployed from a deliverycatheter;

FIGS. 38 to 40 are views of a luminal prosthesis in situ with a valvebeing deployed in the lumen of the luminal prosthesis.

FIG. 41 is an elevational view of a valve according to anotherembodiment of the invention;

FIG. 42 is an enlarged view of a detail of the support structure of thevalve of FIG. 41;

FIGS. 43 and 44 are isometric views of the valve of FIGS. 41 and 42being deployed from a delivery catheter;

FIG. 45 is an elevational view of a prosthesis with the valve of FIGS.43 and 44 in situ;

FIG. 46 is an enlarged view of a detail of the engagement of the valvesupport structure of

FIGS. 41 to 45 engaged in the mesh of the prosthesis;

FIG. 47 is an enlarged view of part of the luminal prosthesis and valvesupport structure of FIG. 46;

FIG. 48 is an elevational view of a luminal prosthesis;

FIG. 49 is an elevational of an esophageal valve of the invention;

FIGS. 50 to 55 are elevational views of steps involved in deploying thevalve of FIG. 49 into a pre-deployed luminal prosthesis of FIG. 48;

FIG. 56 is an elevational view of the valve of FIG. 49 deployed in theluminal prosthesis of FIG. 55;

FIG. 57 is an elevational view similar to FIG. 56 with the valve beingremoved from the deployed prosthesis;

FIG. 58 is an isometric view of a valve according to the invention;

FIG. 59 is an elevational view of the valve of FIG. 56;

FIG. 60 is a plan view of the valve of FIGS. 58 and 59 with the valve ina closed configuration;

FIG. 61 is a plan view similar to FIG. 60 with the valve in an openconfiguration;

FIGS. 62 and 63 are side views of the device of FIG. 60 with the valvein a closed configuration;

FIGS. 64 and 65 are side views of the device of FIG. 60 with the valvein the open configuration;

FIG. 66 is an illustration of a gastrointestinal implant deviceaccording to one embodiment of the invention;

FIG. 67 is an enlarged view of detail A of FIG. 66;

FIGS. 68 and 69 are illustrations of another gastrointestinal implantdevice located in the pyloric sphincter;

FIGS. 70 and 71 are illustrations similar to FIGS. 66 and 67 with thedevice located distal of the pyloric sphincter;

FIG. 72 is an isometric view of a luminal prosthesis of an implantdevice of the invention;

FIG. 73 is an elevational view of a valve, sleeve and scaffold part ofan implant device;

FIG. 74 is an elevational, partially cross sectional view of an implantdevice with a prosthesis located in a lumen such as the pylorus and avalve, sleeve and scaffold for mounting to the prosthesis;

FIG. 75 is an elevational view of the device of FIG. 72 assembled;

FIG. 76 is an elevational view of the device of FIG. 75 with the sleeveextended;

FIG. 77 is an elevational, partially cross sectional view of the device,in situ;

FIG. 78 is a view similar to FIG. 77 of an implant device with a sleevein one folded delivery configuration;

FIG. 79 is a view similar to FIG. 78 with the sleeve in another foldeddelivery configuration;

FIG. 80 is a view similar to FIG. 79 with the sleeve in a further foldeddelivery configuration;

FIG. 81 is an elevational, partially cross sectional view of an implantdevice including a retaining ring for a sleeve;

FIG. 82 is a view similar to FIG. 81 of another sleeve;

FIG. 83 is a view similar to FIG. 81 with a sleeve having a plurality ofretaining rings;

FIG. 84 is cross sectional view illustrating a first stage in thedelivery of an implant device to the pylorus;

FIG. 85 is a cross sectional view of the implant device in position withthe sleeve in a retracted configuration;

FIG. 86 is a cross sectional view of the implant device in situ, withthe sleeve partially extended;

FIG. 87 is a cross sectional view similar to FIG. 86 with the sleevefurther extended;

FIG. 88 is an enlarged cross sectional view of a distal end of thedelivery system;

FIG. 89 is a cross sectional view of the implant device in situ with thesleeve extended and the delivery system being removed;

FIG. 90 is an elevational view of a delivery catheter for the implantdevice;

FIG. 91 is a cross sectional view of the delivery catheter of FIG. 90with a capsule containing the implant device;

FIGS. 92 to 94 are views showing the delivery system at various stages;

FIG. 95 is a cross sectional view of a proximal end of the deliverysystem capsule;

FIG. 96 is an elevational view of part of the delivery system;

FIG. 97 is an exploded view of part of delivery system of FIG. 96;

FIG. 98 is a graph of pressure profile over time with various fixedorifice restrictors;

FIG. 99 is a graph of pressure profile over time with a fixed orificerestriction and an implant device comprising a valve of the invention;

FIG. 100 is a graph of pressure profile over time with a fixed orificerestriction and implant devices comprising valves of the invention;

FIG. 101 is an isometric view of part of a sleeve according to theinvention;

FIG. 102 is a cross sectional view of the sleeve of FIG. 93;

FIG. 103 is an isometric view of part of another sleeve according to theinvention;

FIG. 104 is an isometric view of a luminal prosthesis according to theinvention;

FIG. 105 is an isometric view of another luminal prosthesis according tothe invention

FIGS. 106 and 107 are views of a luminal prosthesis in which inner andouter regions are connected by struts or vines;

FIGS. 108 and 109 are views of a continuous stent which has been foldedor partially inverted to generate two coaxial regions;

FIG. 110 is an illustration of the longitudinal shortening of a stentresulting in migration of a valve device;

FIG. 111 are views of a stent with restricting loops for restrictingexpansion of a section of a self expanding stent;

FIGS. 112 and 113 are views of stents with restricting loops;

FIG. 114 is an isometric view of another luminal prosthesis according tothe invention;

FIG. 115 is a view of the prosthesis of FIG. 114 with a valve andscaffold in position;

FIG. 116 is a plan view showing the valve in a closed configuration;

FIG. 117 is an isometric view of an obesity treatment device in situincorporating the device of FIGS. 114 to 116;

FIG. 118 is an isometric view of a precursor to another luminalprosthesis according to the invention;

FIG. 119 is a view of the precursor of FIG. 118 being folded;

FIG. 120 is a view of a luminal prosthesis formed from the precursor ofFIG. 118;

FIG. 121 is a view of the luminal prosthesis of FIG. 120 with a valveand scaffold in situ;

FIG. 122 is an isometric view of an obesity treatment device in situincorporating the device of FIGS. 120 and 121;

FIG. 123 an isometric view of a further luminal prosthesis according tothe invention;

FIGS. 124 and 125 are diagrams illustrating different configurations ofthe prosthesis of FIG. 123;

FIG. 126 is an isometric view of a still further luminal prosthesisaccording to the invention;

FIGS. 127 to 129 are diagrams illustrating different configurations ofthe prosthesis of FIG. 126;

FIG. 130 is an isometric view of a further luminal prosthesis accordingto the invention;

FIG. 131 is an isometric view of another luminal prosthesis according tothe invention;

FIG. 132 is an isometric view of a still further luminal prosthesis ofthe invention;

FIG. 133 is a side, partially cross sectional view of an obesitytreatment device according to the invention;

FIG. 134 is an isometric view of a valve, internal support and sleeve ofthe device of FIG. 33;

FIG. 135 is an isometric view of an external support of the device ofFIG. 133;

FIG. 136 is an exploded view illustrating the mounting of the valve,internal support and sleeve of FIG. 134 to the external support of FIG.135;

FIG. 137 is a cross sectional view of the obesity treatment device ofthe invention, in use;

FIG. 138 is am enlarged cross sectional view of the obesity treatmentdevice in situ, in one configuration; and

FIG. 139 is a view similar to FIG. 140 with the device in anotherconfiguration of use.

DETAILED DESCRIPTION

Referring to the drawings and initially to FIGS. 1 to 16 thereof thereis illustrated a valve 1 which can open automatically in one direction.

The valve 1 comprises a polymeric valve body having a proximal outersupport region with a rim 2, at least three valve leaflets 3, 4, 5, anda main body region 6 extending between the support rim 2 and the valveleaflets 3, 4, 5. The valve leaflets 3, 4, 5 extend inwardly anddistally and terminate at distal end faces 7, 8, 9 respectively. Theleaflets each 3, 4, 5 have legs a, b which extend at an included angleof 120° to each other. The adjacent pairs of legs 3 a; 4 a; 4 b; 5 b; 5a; 3 b; co-apt to close the gap between the valve leaflets when thevalve is in the normally closed configuration.

The valve 1 has two configurations. The first configuration is anormally closed configuration in which the valve leaflets 3, 4, 5 co-aptto close the valve. The second configuration is an open configuration inwhich the valve leaflets 3, 4, 5 are opened such that the leaflet legpairs 3 a; 4 a; 4 b; 5 b; 5 a; 3 b are opened and spaced-apart inresponse to a force F1 to allow flow through the valve.

The various configurations of the valve 1 are illustrated in FIGS. 11 to16. In the first or normally closed configuration (FIGS. 11, 14) thevalve leaflets 3, 4, 5 co-apt. When a force F1 is applied to the valveleaflets 3, 4, 5 the leaflet legs pairs 3 a; 4 a; 4 b; 5 b; and 5 a; 3 bopen to allow antegrade flow to pass (FIGS. 12, 16). FIG. 15 illustratesa partially open configuration in response to flow. When the force F1 isremoved the leaflets 3, 4, 5 return to the closed position under theinherent biasing of the polymeric material of the valve body (FIG. 13).

The valve leaflets 3, 4, 5 are reinforced in the region of co-aption. Inthis case, this is achieved by a local thickening of the polymericmaterial in this region. Similarly the support rim 2 is reinforced by alocal thickening of the polymeric material.

The region of co-aption of the valve leaflets 3, 4, 5 has an axialextent which is typically from 1 to 5 mm. This ensures positiveco-aption of the leaflets across a significant interfacial area when thevalve is in the normally closed configuration. The thickness of theleaflets at the region of co-aption is typically between 0.1 mm and 10mm.

The valve body has a generally concave outer face and a generally convexinner face.

The valve 1 of the invention returns to its original working positionafter being fully opened. This is accomplished without damaging theworking valve.

When the valve is opened by stomach emptying the leaflets open.

One important characteristic influencing the functioning of the valve isthe leaflet legs that impinge on one another. By varying the geometryand length of the leaflets 3, 4, 5 the valve 1 can be made to open atdifferent pressures. Opening is also dependant on the elasticity anddensity of the material the device is made from. Additionally, theoverall diameter and the diameter to which the leaflets open influencethe opening force.

The valve may be of any suitable biocompatible polymeric material. Itmay be of a biocompatible polymeric material having properties whichallow the valve to function as described.

The materials used for the production of this valve have a % elongationbetween 50% and 3000%. The material also has a tensile strength ofbetween 0.01 and 5 MPa. Additionally the material could have anantimicrobial action to prevent colonisation when in-vivo. Additionallythe material can be elastic or viscoelastic and can optionally be anopen cell foam. The density of the material should be between 0.1 g/cm3to 1.5 g/cm3.

The valve of the invention may be mounted to any suitable luminalprosthesis, especially a prosthesis or stent. The rim 2 of the valveprovides a mounting ring for mounting within the stent 20, for example,the valve 1 may be mounted to the stent by suturing the rim 2 to thestent mesh using sutures 21 as illustrated in FIGS. 18 and 19.

The stent may be of any suitable type. An uncoated or unsleeved stent 20is illustrated in FIGS. 17 to 19. Alternatively, if it is desired toprevent tissue ingrowth a stent 30 having a sleeve 31 may be used (FIGS.20 to 23). In this case the sleeve 31 is external of the stent. In othercases there may alternatively or additionally be an internal sleeve.Further, the stent may have a coating.

A valve such as described above may also be placed into a pre-deployedluminal prosthesis.

In one case a valve 100 may have a co-axial support structure orscaffold 102 is shown in FIGS. 24 and 25. The scaffold 102 is designedto engage with any suitable esophageal stent 140 as illustrated in FIG.29. The mechanism of engagement can be by protrusions which may forexample be proximal and/or distal apices 103 of the scaffold 102 whichengage into the mesh of the existing pre-deployed stent 140.Alternatively or additionally, the scaffold 102 may have features 150designed to hook onto the inside of the struts of an esophageal stent asillustrated in FIGS. 31 and 32.

Referring to FIGS. 26 and 27 there is illustrated a valve 110 accordingto another embodiment of the invention in which the support structure orscaffold 102 tapers distally outwardly so that distal apices 111 of thescaffold engage with the mesh of the existing pre-deployed host stent140.

Referring to FIG. 28 there is illustrated another valve 120 according tothe invention in which the support structure or scaffold 102 tapersdistally inward so that proximal apices 121 of the scaffold 102 engagewith the mesh of an existing pre-deployed stent 140.

The radial force of the scaffold 102 may exert enough friction to holdthe valve in place without the necessity for protrusion. In anotherembodiment a surgical adhesive may be used to secure the retrofittedvalve into place.

Referring to FIGS. 33 to 37 a valve 100 is loaded into a delivery system130 for deployment. The outer diameter of the delivery system 130 issmaller than the inner diameter of a pre-deployed esophageal stent 140.The delivery system 130 in this case comprises a delivery catheterhaving a distal pod 131 in which a valve is housed in a contractedconfiguration. The catheter has a tapered distal tip 132 to avoidsnagging on a pre-deployed stent 140. The pod 131 is axially movablerelative to the tip 132 to release the valve from the pod 131.

The delivery system 130 is used to deliver the valve to a pre-deployedstent 140 as illustrated in FIG. 38. The stent 140 has a mesh and thescaffold of the valve is adapted to engage with the mesh of thepre-deployed stent 140 on release of the valve from the deliverycatheter as illustrated particularly in FIGS. 39 and 40.

Referring to FIGS. 29 to 32 there is illustrated an idealised stent 140with a valve support scaffold 102 in situ. Details of a valve areomitted from these drawings for clarity. In this case the scaffold 102is located at the upper proximal end of the stent. In this case thescaffold 102 has hook-like members 150 for engagement with the mesh ofthe stent 140 as illustrated in FIGS. 31 and 32. The interengagementbetween the stent 140 and the scaffold 102 ensures that the scaffold 102and hence the valve which is fixed to it is retained in position andprovides an anti-proximal migration mechanism.

In the cases illustrated the valve supporting scaffold 102 is of a selfexpanding material such as a shape memory material, for example Nitinol.The valve and scaffold are loaded into the delivery catheter pod 131 ina compressed/reduced diameter configuration. When the constraint of thepod 131 is removed at the deployment site, the scaffold and valve selfexpand to the normal configuration in which the scaffold is engaged withthe pre-deployed host stent 140. In some arrangements the scaffold maybe of an expensile material which is expanded by an expander such as aballoon or the like.

Referring to FIGS. 41 to 44 there is illustrated another valve device151 according to the invention which is similar to that described aboveand like parts are assigned the same reference numerals. In this casethe valve 1 is housed within a support structure or scaffold 102 and isplaced into the lumen of a stent 140 as illustrated in FIGS. 45 to 47.The support structure may comprise a relatively short length (typically40 mm) of a mesh made from a shape memory material such as Nitinol. Themesh may be formed by laser cutting and/or may be of woven construction.Deployment into the lumen of the host stent 140 is via self expansionfrom a radially collapsed state within a delivery catheter 130 as shownin FIGS. 43 and 44. The device 151 is held in place within the stent 140by means of specific interaction mechanisms that increase the axialfriction of the support structure 102. FIGS. 45 to 47 illustrate theinteraction with the host stent 140. In this embodiment the supportstructure 102 has a series of loops or protrusions 155 extendingperpendicularly from its surface. These protrusions 155 engage with thestructure of any host stent 140 by interlocking with the existing meshas shown in FIGS. 52 and 53. The apical tip of each protrusion 155 is inthis case rounded or designed so as to be non-traumatic to any tissuethat may come into contact with the protrusion 155. The intrinsic radialforce of the support structure 102 as well as the flexural strength ofthe protrusions 155 interact to effect the retention performance of thesupport structure 102. Thus the stiffness or flexural strength of theprotrusion 155 and the radial force of the support structure 102 may bemodified to change the interlocking capability and retention performanceof the device.

The valve device 151 is also readily radially collapsible by distal andproximal drawstrings 170, 171. The distal drawstring 170 passes througheyelets 172 mounted to the support structure 102 at the distal end ofthe valve device 151. The distal drawstring 170 has an accessible pullstring 173 which, on pulling, pulls the drawstring 171 inwardly and thusreduces the diameter of the distal end of the support structure 102.Similarly the proximal drawstring 171 passes through eyelets 175 mountedthe support structure 102 at the proximal end of valve device 151. Theproximal drawstring 171 has an accessible pull string 177 which, onpulling, pulls the drawstring 171 inwardly and thus reduces the diameterof the proximal end of the support structure 102. The pull strings 173,177 can be readily gripped using a suitable instrument such as a grasperto draw the proximal and distal ends of the support structure 102inwardly for ease of removal of the valve device 151.

Referring to FIGS. 48 to 57 there is illustrated another valve device200 according to the invention which is similar to that described aboveand like parts are assigned the same reference numerals. In this casethe valve 1 is housed within a support structure or scaffold 102 and isplaced into the lumen of a stent 140 as illustrated in FIGS. 53 to 56.The support structure 102 may comprise a relatively short length(typically 40 mm) of a mesh made from a shape memory material such asNitinol. The mesh may be formed by laser cutting and/or may be of wovenconstruction. Deployment into the lumen of the host stent 140 is viaself expansion from a radially collapsed state within a deliverycatheter 130 as shown in FIGS. 50 to 55. The device 200 is held in placewithin the stent 140 by means of specific interaction mechanisms thatincrease the axial friction of the support structure 102. FIG. 56illustrates the interaction with the host stent 140. In this embodimentthe support structure 102 has a series of loops or protrusions 155extending perpendicularly from its surface. These protrusions 155 engagewith the structure of any host stent 140 by interlocking with theexisting mesh as shown in FIG. 56. The apical tip of each protrusion 155is in this case rounded or designed so as to be non-traumatic to anytissue that may come into contact with the protrusion 155. The intrinsicradial force of the support structure 102 as well as the flexuralstrength of the protrusions 155 interact to effect the retentionperformance of the support structure 102. Thus the stiffness or flexuralstrength of the protrusion 155 and the radial force of the supportstructure 102 may be modified to change the interlocking capability andretention performance of the device.

The valve device 200 is also readily radially collapsible by distal andproximal drawstrings 170, 171. The distal drawstring 170 passes througheyelets 172 mounted to the support structure 102 at the distal end ofthe valve device 200. The distal drawstring 170 has an accessible pullstring 173 which, on pulling, pulls the drawstring 171 inwardly and thusreduces the diameter of the distal end of the support structure 102.Similarly the proximal drawstring 171 passes through eyelets 175 mountedthe support structure 102 at the proximal end of valve device 200. Theproximal drawstring 171 has an accessible pull string 177 which, onpulling, pulls the drawstring 171 inwardly and thus reduces the diameterof the proximal end of the support structure 102. The pull strings 173,177 can be readily gripped using a suitable instrument such as a grasperto draw the proximal and distal ends of the support structure 102inwardly for ease of removal of the valve device 200.

It will be noted that in the case of this device 200 the diameter of thesupport scaffold is relatively uniform and the proximal and distal ends201, 202 of the device 200 are not tapered. We have found that theinterengagement of the rounded protrusions 155 in interstices defined inthe mesh structure of the stent 140 is sufficient to retain the device200 in position in the stent 140. Typically, the diameter of theexpanded support structure 102 will be slightly larger, for example 1 to5% larger than that of the host stent 140 at the desired deploymentlocation to assist in maintaining the scaffold 102 in situ.

In some cases, as illustrated in FIG. 57 the devices of the inventionsuch as the device 200 may be a radially collapsed state if it isdescribed to re-position the valve device 200 with the stent 140 or towithdraw the device 200, for example for replacement and/or forreplacement of the host stent 140.

Thus, the collapsibility of the valves enables its optional removal bydisengagement of the protrusions 155 from the host stent 140, thuseliminating any axial friction associated with the host stent 140.

The valve of FIGS. 1 to 57 may be relatively short and is typically lessthan 30 mm, less than 25 mm, less than 20 mm, less than 15 mm and istypically about 10.6 mm long with an outer rim diameter of 18 mm orabout 11 mm long for an outer rim diameter of 20 mm.

The valve may have any desired number of leaflets, for example the valve300 illustrated in FIGS. 58 to 65 has six valve leaflets 333. Theseleaflets 333 are oriented perpendicular to direction of food flow toadditionally allow greater distensibility of the valve aperture.

Referring to FIGS. 58 to 65 there is illustrated another valve deviceaccording to the invention. The device 300 comprises a valve 301 whichcan open automatically in one direction.

The valve 300 comprises a polymeric valve body having a proximal outersupport region with a rim 302, six valve leaflets 303, and a main bodyregion 306 extending between the support rim 302 and the valve leaflets303. The valve leaflets 303 extend inwardly and distally and terminateat distal end faces 303 respectively. The leaflets each 303 have legswhich extend at an included angle of 60° to each other. The adjacentpairs of legs co-apt to close the gap between the valve leaflets 303when the valve is in the normally closed configuration.

The valve 300 has two configurations. The first configuration is anormally closed configuration in which the valve leaflets 303 co-apt toclose the valve. The second configuration is an open configuration inwhich the valve leaflets 303 are opened such that the leaflet leg pairsare opened and spaced-apart in response to a force F1 to allow flowthrough the valve 300.

The various configurations of the valve 1 are illustrated in FIGS. 58 to65. In the first or normally closed configuration the valve leaflets 303co-apt. When a force F1 is applied to the valve leaflets 303 the leafletlegs pairs open to allow flow to pass. When the force F1 is removed theleaflets 303 return to the closed position under the inherent biasing ofthe polymeric material of the valve body.

The valve leaflets 303 are reinforced in the region of co-aption. Inthis case, this is achieved by a local thickening of the polymericmaterial in this region. Similarly the support rim 302 is reinforced bya local thickening of the polymeric material.

The region of co-aption of the valve leaflets 303 has an axial extentwhich is typically from 1 to 5 mm. This ensures positive co-aption ofthe leaflets across a significant interfacial area when the valve is inthe normally closed configuration. The thickness of the leaflets at theregion of co-aption is typically between 0.1 mm and 10 mm.

The valve body 306 has a generally concave outer face and a generallyconvex inner face.

The valve 300 of the invention returns to its original working positionafter being fully opened. This is accomplished without damaging theworking valve.

An important characteristic influencing the functioning of the valve 300is the leaflet legs that impinge on one another. By varying the geometryand length of the leaflets 303 the valve 300 can be made to open atdifferent pressures. Opening is also dependant on the elasticity anddensity of the material the device is made from. Additionally, theoverall diameter and the diameter to which the leaflets open influencethe opening force.

The valve may be of any suitable biocompatible polymeric material. Itmay be of a biocompatible polymeric material having properties whichallow the valve to function as described.

The materials used for the production of this valve have a % elongationbetween 50% and 3000%. The material also has a tensile strength ofbetween 0.01 and 5 MPa. Additionally the material could have anantimicrobial action to prevent colonisation when in-vivo. Additionallythe material can be elastic or viscoelastic and can optionally be anopen cell foam. The density of the material should be between 0.1 g/cm3to 1.5 g/cm3.

The valve 300 of the invention may be mounted to any suitable luminalprosthesis. The rim 302 of the valve provides a mounting ring formounting within the prosthesis, for example, the valve 300 may bemounted to the stent by suturing the rim 2 to the stent mesh usingsutures.

Many emerging obesity treatments involve the placement of a tube intothe duodenum, which restricts the absorption of certain nutrients atthis point in the body. The resulting calorific deficit then results inweight loss. Some of these devices can cause the pyloric valve to beopened for prolonged periods thus causing rapid stomach emptying. Duringepisodes of rapid stomach emptying the feeling of fullness is shortenedand thus the patient eats more.

We have found that by placing a valve device at or near the pylorus thatcan controllably restrict the rate of stomach emptying then a feeling offullness or satiety can be gained.

Referring to FIGS. 66 and 67 there is illustrated a valve device 500that can be retrospectively placed into an existing obesity treatmentdevice such as a sleeve 501 which extends from a stomach 502 into theduodenum 503. One such sleeve device is described in US2005/0125075A,the entire contents of which are incorporated herein by reference. Thevalve 500 functions to restrict the rate of stomach emptying. Thepositioning of the valve 500 within a pre-positioned sleeve 501 isillustrated in FIGS. 66 and 67. The valve 500 may be of the typedescribed above and may be attached to a scaffold 505 as describedabove.

Referring to FIGS. 68 and 69 there is illustrated a valve 550 of theinvention which in this case is placed in a pyloric sphincter 551 inorder to control the rate of stomach emptying and thereby provide anenhanced feeling of satiety. This approach may be used, if example inassociation with gastic banding or other obesity treatment system. Thevalve 550 may be retained in situ by any suitable means such as anchors552.

Alternatively, as illustrated in FIGS. 70 and 71 the valve 550 may belocated distal of the pyloric sphincter 551 to provide a further valveacting in series with the pyloric valve or sphincter.

Referring to FIGS. 72 to 77 there is illustrated a gastrointestinalimplant device 600 which comprises a sleeve 601 for extending into theduodenum and an artificial valve 602 for placement at the pylorus 603 tocontrol flow from the stomach 604 into the duodenum which is lined byduodenal sleeve 601. The device 601 also comprises a support structurefor the valve. In this case the support structure comprises a scaffold605 to which the valve 602 is mounted. The support structure alsocomprises a luminal prosthesis 606 to which the scaffold is mounted. Inthis instance, the scaffold 605 is releasably mountable to the luminalprosthesis 606. The sleeve 601 is mounted to the support structure andin this case to the valve and/or the scaffold 605.

In this case the support structure comprises a stent-like scaffold 605and the luminal prosthesis 606. The prosthesis 606 is for deployment atthe pylorus and the scaffold 605 to which the valve 602 is mounted isreleasably mountable to the pre-deployed luminal prosthesis 606. Thescaffold comprises engagement elements which are releasably engagablewith the luminal prosthesis 606. The engagement elements may compriseprotrusions 607 which are releasably engagable with the luminalprosthesis. The luminal prosthesis 606 in this case comprises a meshwhich may have a coating thereon. The protrusions 609 may engage withand in some cases penetrate the mesh. In the case of a coating on themesh the protrusions 607 may penetrate the coating.

In this embodiment at least a part of the implant device is removablefor complete removal, re-positioning, or replacement. There is a releasemeans for releasing the scaffold 605 from engagement with the prosthesis606. The release means in this case comprises means for reducing thediameter of at least portion of the scaffold. The release means maycomprise a drawstring 611 extending around the scaffold 605. In thiscase there is a first drawstring 611 a extending around a proximal endof the support structure and a second drawstring 611 b extending arounda distal end of the support structure. For removal, the drawstrings aretightened by pulling on the loops 612 using a suitable instrument suchas a grasper.

Both the prosthesis 606 and the scaffold 605 may be of a shape memorymaterial such as Nitinol and have a reduced diameter deliveryconfiguration and an expanded deployed configuration.

The prosthesis 606 in this case comprises a proximal flare 620 forlocation, in the expanded configuration at the antrum of the pylorus.The flare 620 assists in anchoring the prosthesis in position. Theprosthesis 606 in this case also has a distal bulbous region 621 whichassists in anchoring the prosthesis in position. The prosthesis 606 hasa scaffold receiving region 622 which in this case is intermediate theproximal and distal ends of the prosthesis 606.

The scaffold 605 has a proximal region 630 to accommodate the valve 602and a distal region 631 to accommodate the sleeve 601 in a retracteddelivery configuration. The valve 602 may be attached to the scaffold605 by sutures 632 and/or may be bonded, for example by adhesive bondingto the scaffold 605.

The sleeve 601 in this case is also attached to the scaffold 605 and/orto the valve 602, for example by bonding and/or sutures.

The valve 602 has a normally closed configuration and an openconfiguration in which the valve is opened for stomach emptying. Thevalve 602 is adapted to open automatically for stomach emptying and toreturn automatically to the closed configuration. The valve may be of aviscoelastic foam material such as the foam materials described indetail in this specification. The valve 602 is in this case similar tothe valves described earlier and comprises an outer support region 640,at least three valve leaflets 641, and a main body region 642 extendingbetween the support region and the valve leaflets 641. The valve 602 hasa region 643 of co-aption of the valve leaflets in the closedconfiguration to maintain the valve in the normally closedconfiguration. The region 643 of co-aption may extend for an axiallength of at least 1 mm.

FIG. 72 shows the luminal prosthesis 606 in a relaxed, pre-loadingconfiguration. FIG. 73 shows the scaffold 605, valve 602 and sleeve 601.The sleeve 601 is in a retracted configuration. FIG. 74 shows theprosthesis 606 deployed at the pylorus and the scaffold 605/valve602/sleeve 601 being inserted into the prosthesis 606. FIG. 75 shows thescaffold 605/valve 602/sleeve 601 deployed in the prosthesis 606. FIG.76 is a view similar to FIG. 75 with the sleeve 601 expanded into adeployed configuration extending through the duodenum. FIG. 77 is across sectional view showing the valve 602, support structure and sleeve601 fully deployed.

It will be appreciated that the sleeve may be configured in differentways in a retracted delivery configuration. Some examples are shown inFIGS. 78 to 80. In FIG. 78 the sleeve 601 is folded somewhat like anaccordion. In FIG. 79 the sleeve 601 may be folded longitudinally andmay subsequently be spirally wound. In FIG. 80 the sleeve 601 haslongitudinal pleats or folds and is also folded over transversely.

The sleeve 601 may be of constant diameter along the length thereof ormay be tapered (FIGS. 81/83) or may have a narrowed proximal section anda constant diameter distal section (FIG. 82).

The sleeve 601 may have a retaining means to assist in retaining thesleeve at a desired location. For example, as illustrated in FIG. 81 thesleeve 601 may have a retaining ring 650 at or near the distal end ofthe sleeve. There may be a plurality of such retaining rings 650 whichmay be spaced-apart along the sleeve 601 as illustrated in FIG. 83. Therings 650 may be of different size and/or shape to suit the targetanatomy. The retaining rings 650 may have a biasing means to bias theminto an enlarged configuration. For example, the retaining ring 650 maybe oversized with respect to the diameter of the sleeve 601. There maybe a release means such as a drawstring or the like to release theretaining ring 650 from the expanded deployed configuration.

Referring to FIGS. 84 to 89 an implant device according to the inventionand an associated delivery system are illustrated. The delivery systemcomprises a delivery catheter 660 with a distal capsule 669 whichcontains the scaffold 605, valve 602 and sleeve 601 in the retractedconfiguration. The delivery system includes a proximal expandableelement provided by an inflatable proximal balloon 662 and a distalexpandable element provided by a distal balloon 663. The proximalballoon 662 provides a temporary seal with the proximal end 664 of thesleeve 601 at the proximal side of the valve 602. The distal balloon 665provides a temporary distal seal between a distal olive 666 and a distalend 667 of the sleeve 601. An inflation fluid is introduced into thesleeve 601 between the proximal and distal balloons 662, 665, the fluidcauses the sleeve 601 to expand axially to the expanded deployedconfiguration. When the sleeve 601 is in the extended deployedconfiguration the distal balloon 665 is deflated, allowing the olive 666to detach and travel distally. The rest of the delivery system can thenbe withdrawn proximally, leaving the implant device in situ. FIG. 84illustrates the luminal prosthesis or stent 605 with a 30 mm wideproximal flare placed across the pylorus with the proximal flare restingagainst the pyloric antrum. An endoscope with a delivery system isadvanced into the stomach. The delivery device is controlled through theshaft of the endoscope and comprises a capsule that is positionedproximal to the endoscope. The capsule is advanced to the pre-placedstent. FIG. 85 shows the stent, scaffold and valve with the sleeve inthe retracted configuration. The distal olive 666 of the delivery systemis also shown.

Referring to FIG. 86, water is flushed through the delivery system toelongate the plastic sleeve, which passes through the duodenum past theligament of trietz.

Referring to FIG. 87, when the implant device is deployed the deliverysystem is removed and the distal olive 666 passes through the intestine.

In the case of the delivery system of FIGS. 84 to 89 the valve andscaffold are deployed before the sleeve is deployed. In this arrangementthe proximal seal is provided by the proximal balloon which sealsagainst the valve as illustrated in FIG. 87.

Referring to FIGS. 90 to 97 there is illustrated another deliverysystem. In this case the valve and scaffold are deployed afterdeployment of the sleeve. In this arrangement the proximal seal isprovided by the proximal balloon 662 which in this case seals againstthe inner wall of a distal capsule 669. The balloon 662 is not fullyinflated in FIGS. 91, 92 and 94. A delivery catheter comprises an outershaft 680 with a retraction hub 681 and an inner shaft 682. The shafthas various lumens and at the proximal end there are various portsconnected with the lumens. There is a proximal sleeve inflation port683, a distal tip balloon inflation port 684, a proximal seal or plungerballoon inflation port 685. There is also a guidewire port 686 (which isillustrated in FIG. 96) for a guidewire 687. FIG. 97 shows the variouslumens,—a water injection lumen 690 for deployment of the sleeve,—aproximal balloon inflation lumen 691, a distal tip balloon inflationlumen 692 and a guidewire lumen 693. A flexible tube 688 extends througha lumen 689 in the inner shaft 682. The flexible tube 688 also extendsthrough the proximal balloon 662 which in this case is of doughnutshape. The tube 688 has an outlet for inflation of balloon 665.

Referring to FIG. 90 the capsule 669 is mechanically releasable from theouter sheath, for example through a screw thread connection 695. In use,the shaft of the delivery system is inserted through the proximal end ofa delivery channel of an endoscope. When the distal end of the shaft ofthe delivery shaft exits the distal end of the endoscope deliverychannel the capsule is mounted to the distal end of the delivery shaftusing the mechanical attachment which in this case is a screw-inattachment.

In FIG. 90 the sleeve/valve/scaffold implant device is in the retracteddelivery configuration. The flexible tube 688 extends to the tip balloon665 and has a hole through which air is delivered for inflation of theballoon 665. The tube 688 is of a suitable flexible material such as aplastics, for example nylon.

Referring to FIG. 92, the proximal balloon 662 is inflated to seal thesleeve 601 at the proximal end and the distal balloon 665 is inflated toseal the sleeve 601 at the distal end. Water is then flushed into theretracted sleeve 601 and by virtue of the seals 662, 665 at the proximaland distal ends, the water fills the sleeve 601, causing it to extend.The sleeve 601 is shown in a partially extended configuration in FIG.92.

When the sleeve 601 has fully extended (FIG. 93) the distal balloon 665is deflated, allowing the tip 666 to float into the intestine fordischarge. The proximal balloon 662 remains inflated and acts as aplunger to deploy the scaffold from the capsule 669. The scaffold 605engages with the stent 606 as described above and the delivery system iswithdrawn as illustrated in FIG. 94.

FIG. 95 illustrates the proximal delivery components. The retraction hub681 is connected to the outer shaft to enable withdrawal of the outershaft 680 over the inner shaft 682.

FIG. 98 is a graph of the pressure profile of fixed orifice restrictorswith various size orifices. The restrictions were created using a 1 mmthick polyethylene membrane. Each orifice was created by drilling outthe desired hole size followed by verification using a Vernier calliper.The flowrate through the test fixture was controlled at 7.86 g/sec witha fluid having a viscosity of 39,000 Cps. It will be noted that when aseries of fixed diameter orifice restrictors are used to impede fluidflow, the resulting back-pressures generated have a distinctive pattern.The back-pressure initially rises sharply followed by a sustainedgradual pressure rise until flow is stopped. This behaviour isillustrated by FIG. 98 for 4 mm, 5 mm and 6 mm diameter restrictions.This is undesirable for use as a flow restrictor in the stomach becausea constant rise in pressure as a function of flow might give rise togastric distress and cramping.

FIG. 99 is a pressure profile of various different restrictions. The 6mm orifice is made as described above for FIG. 98. The pressure profilerepresented by interrupted lines is generated using a leaflet valve asdescribed above with reference to FIGS. 58-65. The valve is of aviscoelastic foam material. The foam material is in this case a materialdescribed in Example 5 of the Group 1 materials described below. Thedensity of the material was 0.9 g/ml. It can be seen from FIG. 99 that acoapting valve of the above description enables the generation of aconstant back-pressure over the duration of fluid flow. The valve isthus adapting to fluid flow to maintain a constant restrictive forceindependent of fluid flow therethrough.

The performance of the valve can be tailored by adjusting the materialdensity, this for example can be achieved by introducing more or lessmaterial into the valve forming mold, which subsequently expands to fillthe cavity. Referring to FIG. 100, the valve was made using the samematerial as in FIG. 99 but in this case the density was changed toapproximately 0.76 g/ml. Through this modification it was possible toproduce a valve that generated an initially high back-pressure andsubsequently adapted to the fluid flow thus lowering the back-pressure.Such a valve has an initial barrier function followed by a steady staterestriction. The valve impedes flow until a pre-determined set-pointpressure after which the back pressure remains substantially constantthus providing a predictable stomach emptying rate.

Various materials can be used for fabrication of the sleeve portion ofthe device. These materials can be for example; polyethylene, PTFE orFEP due to their low friction thus not impeding fluid flow therethrough.

Referring to FIGS. 101 and 102 a sleeve 750 according to the inventionhas means to visualise the deployment of the sleeve using a radiopaquemarker. A radiopague ink or paint is used. Because of the chemicalnature of the sleeve materials the adhesion of a coating is verydifficult. A longitudinal pocket 751 is provided which may be created byoverlapping a portion of the sleeve material. Into this pocket 751 isdeposited a radiopaque material 752 such as a liquid silicon resinfilled with BaSO4, which is subsequently cured. This facilitates a lowprofile and a fluoroscopically distinguishable marker for visualisationin the body. Referring to FIG. 103 in this case the sleeve has aplurality of pockets 760 which may be arranged in any desired manner tofacilitate visualisation, for example at particular locations.

The duodenum begins at the pylorus and forms a curved region immediatelydistal to the duodenal bulb. This region, known as the descendingduodenum, is where chyme begins to mix with digestive secretions fromthe ampulla of Vater. As the chyme begins to digest it is absorbed bythe luminal surface of the duodenum. The sleeve functions to bypass thisabsorption mechanism. The length of the sleeve liner can be sufficientto reach the distal duodenum coincident with the ligament of treitz,where the duodenum meets the Jejunum. Alternatively the sleeve can beshorter and the inhibition of absorption through the duodenal lumen willbe proportional to the length of the sleeve. Given that most of theadsorption in the duodenum happens between the ampulla of Vater andJejunum the sleeve should at least be long enough to traverse theampulla. In addition, when the sleeve does not extend into the ligamentof treitz, the sleeve is more easily delivered as it is not required tonavigate through the tortuosity of the ligament of treitz. The typicallength of the sleeve may be 40 cm to 45 cm.

FIG. 104 is an illustration of a host luminal prostheseis or stent 800according to the invention. The stent 800 comprises a funnel shapedregion 801 to be placed in the antrun of the stomach. The host stentshown in FIG. 84 also has a funnel shaped region to be placed in theantrum of the stomach. Such a funnel shaped or flared region ensuresthat chyme flows through the lumen of the stent and not around theexternal surface of the stent. This is important as chyme being forcedaround the outside of the stent could cause compression and migration ofthe stent.

The funnel region 801 is connected to a softer narrower region 802 thatis designed to traverse the pylorus. This region 802 is sufficientlycompliant to allow the pylorus to close in response to physiologicalpressures.

This softer region 802 also has a means to allow coaxial connection ofan obesity device such as a valve as shown in FIG. 77. The connection ofan obesity device in the proximal part of the stent is important. Bythis methodology any drag force experienced by the obesity device due tofood passage through the lumen can be transferred to other region(s) ofthe stent such as a distal bulbous region(s) 803 of the stent. Theresulting compressive force can expand the bulbous region(s) 803 of thestent structure thus reinforcing the retention of the stent.

Connecting the bulbous region 803 to a trans-pyloric funnel 801 helps tolocate the stent in the anatomy and prevent rotation of the bulb 803perpendicular to the axis of the duodenal lumen.

The stent may also have a cylindrical region 804 that connects to thedistal end of the bulbous region 803 for contacting with the tubularlumen of the duodenum.

The stent is a self expanding stent. The self expanding stent may beproduced by knitting, braiding or weaving. In one case the stent is of abraided structure.

Self expanding braided or knitted stents can be made from either metalor synthetic polymers. If made from metal, a superelastic alloy isusually chosen because of the desired mechanical properties. Thesestents can be designed to exert significant radial force but at the sametime be conformable and allow for the natural mechanical processes ofdigestion.

The technology might be most appropriately used in the gastro intestinaltract as described above.

One of the advantages of braided or knitted stents is that their radialdiameter can be easily reduced to allow sheathing and delivery. Thisproperty is important when the stent is to be introduced into a narrowbody lumen or even through the accessory channel of an endoscope.

However, because of the woven structure, the reduced diameter stent isoften substantially longer than when its diameter is allowed to returnto it's nominal state. This in turn causes a problem during deployment,whereby the stent foreshortens as it expands radially, making accurateplacement a challenge. The user of such stents must always balance theadvantages of their clinical benefit with the difficulty of delivery.

Because of the inter-relationship between the length and diameter ofthese stents, any force in the body that causes their elongation, willcause their diameter to shrink. This mechanical behaviour willultimately result in loss of contact with the body lumen causingmigration. Conversely, any force in the body that causes the stent to belongitudinally shortened will result in an axial expansion thusre-inforcing the stents position in the body lumen.

Such a stent may elongate when a relative tensile force is applied toeither end and may shorten when a compressive force is applied to eitherend.

There are situations in which the use of a valve in a self expandingstent may be desirable and anatomical considerations may dictate thatthe valve be placed either at the proximal or distal end of the stent. Avalve may experience a drag force from the flow of food through itslumen. If the valve is placed at the distal end of the stent, a tensileforce may be created by the flow of food through the stent, whereas acompressive force could be created if the valve is placed at theproximal end of the stent.

Although the latter is more desirable from a retention standpoint it maynot always be possible to position a valve in the proximal stent. Itfollows that valves placed at the distal end of the stent give rise to aheightened risk of migration.

The invention provides methodologies for the transfer of forces,experienced by distally placed valves, to the proximal region of astent. Thus, a proximally placed valve could be made to exert acompressive force on the stent.

The invention may be described broadly as follows: a stent that has anouter region 851 for contact with the body lumen, an inner region 852for contacting with a valve (or such a prosthesis) and a connectingcomponent for connecting the inner region to the proximal part of theouter region. One embodiment is illustrated by FIG. 105. The outerregion may be contoured to fit the appropriate body lumen. Thedimensions indicated in FIG. 105 are particularly appropriate for aprosthesis which is to be located in the antrum of the stomach andextend through the pylorus.

The connecting region may be formed by discrete struts, wires or otherstructures 853 as shown in FIGS. 106 and 107. Alternatively the innerand outer regions may be formed by one continuous stent folded so as toform coaxial inner and outer regions 851,852 FIGS. 108 and 109.

There are situations in which the placement of a valve and supportstructure in an already deployed self expanding stent (host stent) maybe desirable. Such a valve component may anchor itself in the host stentby means of radial force, friction or by some mechanically interlockingmechanism.

Any forces exerted on the stent and valve system that cause the stent toforeshorten and compress will result in an expansion of it's diameter.This behaviour would likely cause any coaxially located valve componentto loose engagement with the inner lumen of the stent and thus migrationwould occur as shown by FIG. 110. FIG. 110 illustrates longitudinalshortening of a stent 825 (such as a braided stent) resulting inmigration of a valve device 826.

One aspect of the invention involves the addition of a non-distensibleloop or series of loops 820 to the circumference of a self expandingstent restricting expansion of a section of a self expanding stent asshown by FIGS. 111, 112 and 113. The loops 820 which may be made from aflexible material such as a polymeric or metallic thread allow radialcompression of the stent during loading but limit radial expansion tothe pre-determined diameter of the loop. Exemplary materials are eithermonofilament or braided polypropylene suture or stainless steel wire.

By using this methodology the valve component, which may be placedwithin the region with added loops, will not be displaced by anylongitudinal forces on the stent.

Referring to FIG. 114 there is illustrated another endoluminalprosthesis 900 according to the invention. The prosthesis is similar tothe prosthesis of FIG. 113 and like parts are assigned the samereference numerals. The prosthesis is of braided mesh construction andcomprises a proximal flare or umbrella region 801, a bulbous region 803and a duodenal region 804. A transpyloric region 901 interconnects theproximal flare 801 around the bulbous region 803.

The proximal umbrella region 801 is of open mesh and is relatively softto avoid tissue irritation. The periphery of the proximal flare is inthis case at least partially coated with a suitable coating material.The coating in this region functions as a deployment aid as it preventssticking between the adjacent regions when the stent is in a collapseddelivery configuration. The turning of the flare distally provides someaxial drag which provides resistance against dislodgment in use, forexample when located at the pylorus.

The transpyloric region 901 is very soft and pliable to resist forcetransmission from the proximal flare 801 to the bulbous region 803. Thetranspyloric region may be uncoated to allow some tissue ingrowth.

The bulbous region 803 acts to assist retention of the device byengaging in the duodenal bulb. The mesh is flexible in this region toadapt to the anatomy in which it is deployed. A lower part of thebulbous region 803 may be coated to prevent tissue ingrowth.

The duodenal region 804 is designed such that its diameter will notexpand beyond a pre-seat limit. The braid/mesh has a weave which is moredense than the other regions as the duodenal region in this case is theregion in which a valve 602 and associated scaffold 605 are deployed—asillustrated in FIGS. 115 to 117. The valve and scaffold may, forexample, be as described above—such as those described with reference toFIGS. 73 to 97.

FIG. 120 illustrates another luminal prosthesis 925 according to theinvention which has some features similar to the prosthesis of FIG. 109having coaxial inner and outer regions 851, 852. In this case the innerand outer regions 851, 852 are formed by one continuous precursor stent935 (FIG. 118) which is folded as illustrated in FIG. 119. The innerregion 852 is in this case adjacent to the proximal end of theprosthesis and a scaffold and valve of the type previously described canbe readily deployed. FIG. 121 shows the luminal prosthesis of FIG. 120with a valve and scaffold in situ. FIG. 122 illustrates an obesitytreatment device according to the invention in situ which incorporatethe device of FIGS. 120 and 121. The arrangement ensures that anymovement of the valve is effectively isolated from any forshortening orotherwise of the outer region of the stent.

Another luminal prosthesis 928 according to the invention is illustratedin FIGS. 123 to 125. This prosthesis 928 is similar to the prosthesis ofFIG. 107 and FIGS. 124 and 125 illustrate how the inner part of theprosthesis is at least partially isolated from the outer part by virtueof the connection 853 which may for example define a region of at leastpartial articulation/hinging/pivoting.

FIG. 126 illustrates another luminal prosthesis 925 according to theinvention which is somewhat similar to the prosthesis of FIGS. 109. Thefunctioning of the prosthesis 925 is diagrammatically illustrated inFIGS. 127 to 129.

A similar prosthesis is illustrated in FIG. 126 and the functioning ofthe device is diagrammatically illustrated in FIGS. 127 to 129.

In some cases, as illustrated in FIGS. 130 and 131 there may be anadditional axially flexible connector such as at least one tether 930between the inner and outer parts.

Referring to FIG. 132, in this case a prosthesis 950 comprises a bulbouspart 951 which is separate from a proximal flare part 952. The parts951, 952 may be interconnected by any suitable connector(s) 953 such asat least one tether. The proximal flare may have a partial transpyloricregion to which a valve/scaffold may be mounted.

Referring to digs 133 to 139, there is illustrated another obesitytreatment device 960 according to the invention. The device 960comprises an external support 961, a valve 962 mounted to an internalsupport 963 and a sleeve 964 which extends in use into the duodenum asdescribed above.

The external support 961 has a proximal flare portion 970 and a distalbulbous region 971. The distal bulbous region and the proximal flareregion are connected view a transpyloric cylindrical region. The radialforce of the cylindrical legion is low to allow normal functioning ofthe pyloric sphincter. The proximal flare portion 970 is of open meshconstruction and does not require a coating. It engages with the antrumof the stomach which retains it in place. At least a distal portion ofthe bulbous region 971 of the external support 961 is coated.

The valve 962 is mounted to the internal support 963 and the internalsupport 963 in turn is engaged with the coated distal portion of thebulbous region 971 of the external support 961. The internal support 963has integral hoops 972 which engage in the mesh of the external support961 to assist in retaining the scaffold 963 in situ. The internalsupport 963 is free to move relative to the external support 961 butdoes not impinge upon the tissue of the duodenal bulb.

In use, when food is passing from the stomach through the valve 962 aproximal portion of the internal scaffold 963 moves relative to theexternal support 961 which causes axial force to be translated bothdistally and radially. The resultant force vector augments the radialforce on the external support 961 and absorbs axial force. The proximalportion of the internal support 963 can move axially distally because itis not coupled to the external support 961. The distal portion of theinternal support 963 only interacts with the external support 961 anddoes not extend through the external support 961. The inner support 961does not engage with the wall of the duodenal bulb.

The obesity treatment device does not interfere with the functioning ofthe pyloric sphincter. The pylorus functions normally whilst ensuringthat the device is anchored in place. When food is passing through thevalve the force applied is translated into a radial force on theduodenal bulb which is sufficiently pliant to distend and absorb thisforce. The device functions to retard the emptying of the stomach togive the user a prolonged feeling of saiety.

In recent years there has been a significant upsurge in commercialactivity related to implantable devices to treat obesity. Some of thesedevices are intended for use in the pylorus and duodenum and thusrequire some form of retention. Current retention modalities include theuse of tissue penetrating barbs, which create ulceration and pain. Thisgastrointestinal implant device avoids the use of such barbs.

This technology will find commercial application in the emerging area ofobesity treatment for improving the retention of devices that will beexposed to the high forces associated with food flow through the GItract.

Various technologies which may be suitable for use in or in associationwith the device of the invention are described in the following USpatent applications:

-   -   U.S. Ser. No. 12/488,037 (published as US2010-0121462A);    -   U.S. Ser. No. 12/488,016 (now U.S. Pat. No. 8,029,557);    -   U.S. Ser. No. 12/487,991 (published as US2010-0121461A);    -   U.S. Ser. No. 12/971,458 (published as US2011-0190905A);    -   U.S. Ser. No. 13/493,904 (published as US2012-0310138A); and    -   U.S. Ser. No. 13/329,728 (published as US2012-0158026A)        the entire contents of all of which are herein incorporated by        reference.

A first Group of biomaterials that are suitable for manufacturing avalve of the invention is described in our U.S. Ser. No. 12/488,047 (nowU.S. Pat. No. 7,932,343) and WO2009/153769, the entire contents of whichare herein incorporated by reference. A second Group of biomaterialsthat are suitable for manufacturing a valve of the invention isdescribed in our U.S. Ser. No. 12/971,384 (published as US2011-0152395A)and WO2011/073967A, the entire contents of which are herein incorporatedby reference.

Various features of the invention are described in detail andillustrated herein. Appropriate features described with reference to oneembodiment may be utilised in addition to and/or as a substitute forfeatures described in other embodiments.

The invention is not limited to the embodiments hereinbefore described,with reference to the accompanying drawings, which may be varied inconstruction and detail.

The invention claimed is:
 1. A luminal prosthesis comprising: a firstpart which is adapted to be retained in a body lumen, the first partincluding a distal portion having a distal end that forms an exitopening of the luminal prosthesis and a proximal portion having aproximal end that forms an entrance opening of the luminal prosthesis,and a bulbous region connected between the distal portion and theproximal portion, with the bulbous region having a lateral width that iswider than a width of the distal portion and wider than a width of theproximal portion, where the distal portion is formed as a firstcylindrical region on a distal side of the bulbous region and theproximal portion is formed as a second cylindrical region on a proximalside of the bulbous region; a second part which is connected to theproximal end of the proximal portion of the first part by a connector; athrough-lumen formed in the luminal prosthesis through the first partand through the second part; and a valve disposed in the through-lumenof the luminal prosthesis; wherein the second part extends a radialdistance from the first part to an outermost flare diameter of thesecond part, with a width of the outermost flare diameter of the secondpart forming a maximum width of the luminal prosthesis.
 2. A prosthesisas claimed in claim 1 wherein the second part has an inner perimeterconnected to the proximal portion of the first part, and the second partextends in a radial direction away from the first part to the outermostflare diameter of the second part, with the outermost flare diameter ofthe second part closer to the distal end of the first part than theinner perimeter of the second part is to the distal end of the firstpart.
 3. A prosthesis as claimed in claim 1 wherein the connectorcomprises a tether.
 4. A prosthesis as claimed in claim 1 wherein theconnector comprises a strut.
 5. A prosthesis as claimed in claim 1wherein the connector comprises a wire.
 6. A prosthesis as claimed inclaim 1 wherein the first part and the second part are formed from asingle precursor.
 7. A prosthesis as claimed in claim 6 wherein theprecursor comprises one continuous stent which is folded to form thefirst part and the second part.
 8. A prosthesis as claimed in claim 1wherein the second part is of open mesh construction.
 9. A prosthesis asclaimed in claim 1 wherein the second part is adapted to resist axialmovement of the luminal prosthesis when the luminal prosthesis is placedin the body lumen.
 10. A prosthesis as claimed in claim 1 wherein thesecond part is at least partially coated with a material.
 11. Aprosthesis as claimed in claim 10 wherein the second part has aperipheral region which is coated with a material.
 12. A prosthesis asclaimed in claim 1 wherein the bulbous region is at least partiallycoated with a material.
 13. A prosthesis as claimed in claim 1 whereinthe first part and the second part comprise a braided mesh construction.14. A prosthesis as claimed in claim 1 having a reinforcement tofacilitate radial compression during loading and to limit radialexpansion after implantation.
 15. A prosthesis as claimed in claim 14wherein the reinforcement extends around at least part of acircumference of the first part and the second part.
 16. A prosthesis asclaimed in claim 15 wherein the reinforcement is a loop.
 17. Aprosthesis as claimed in claim 14 wherein the reinforcement isnon-distensible.
 18. A prosthesis as claimed in claim 14 wherein thereinforcement comprises one of a monofilament suture, braidedpolypropylene suture, and a stainless steel wire.
 19. A prosthesis asclaimed in claim 1 wherein the proximal portion has a proximal portionlength measured from the bulbous region to the entrance opening formedat the proximal end of the first part, and a length of the distalportion is longer than the proximal portion length.
 20. A prosthesis asclaimed in claim 1 wherein the distal portion provides a duodenal regionadapted for placement in a duodenum, with the duodenal region having aduodenal region length measured from the bulbous region to the exitopening formed at the distal end of the first part, and the duodenalregion length is longer than a length of the bulbous region.
 21. Aprosthesis as claimed in claim 1 wherein the connector is one of atether, a strut, and a wire and is provided separately from the firstpart and the second part of the luminal prosthesis.
 22. A prosthesis asclaimed in claim 1 wherein the first part and the second part combine toprovide a self-expanding luminal prosthesis.
 23. A prosthesis as claimedin claim 1 wherein the luminal prosthesis has an outer region adapted tocontact the body lumen, an inner region adapted to receive the valve,and the connector connects the inner region to the outer region.
 24. Aprosthesis as claimed in claim 1 wherein each of the distal portion andthe proximal portion is a braided mesh, and a weave of the braided meshof the distal portion is more dense than a weave of the of the braidedmesh of the proximal portion.
 25. A luminal prosthesis comprising: abulbous region connected between a distal portion and a proximal portionof the luminal prosthesis, with the bulbous region having a lateralwidth that is wider than a width of the distal portion and wider than awidth of the proximal portion; a first cylindrical region formed on adistal side of the bulbous region and a second cylindrical region formedon a proximal side of the bulbous region; a flared part connected to aproximal end of the second cylindrical region by a connector, where theflared part extends a radial distance from the proximal end of thesecond cylindrical region to form an outermost flare diameter thatdefines a maximum width of the luminal prosthesis; a through-lumenformed in the luminal prosthesis through the second cylindrical region,the bulbous region, and the first cylindrical region; a valve disposedin the through-lumen of the luminal prosthesis; and a reinforcement loopextending around at least part of a circumference of the firstcylindrical region.